Premium Member

Have a friend with an '01 SLK230. She complained about rough running and poor acceleration. Pulled the codes the other day and they came up as 301, 335 and 336. I assume there is supposed to be a "P0" in front of each of those. P0301 is misfire cylinder 1. P0335 and P0336 are both crankshaft position sensor codes. The codes were reset and haven't come back on, but it's also only been a day. What would you think would be the approach to fix this? Plugs have not been changed, so it's due for them I think regardless. Could the MAF cause the P0301 code and it that the likely culprit?

Premium Member 2002 SLK230K

Clean the MAF first, if the codes come back its the CPS. I had the same issue this summer, also when ever i got into the throttle heavy i would get a misfire code and end up in limp mode. The new CPS fixed that issue.

Registered

Just did the P0301 on my daughter's Volvo C70 convertible. I'm pretty sure it's the same error (misfire on cylinder one). Hers turned out to be that the coil (coil-on-plug) on cylinder one had failed.

To diagnose I swapped coils and plugs around then would pull the connector to the coil (or the plug wire in the case of a car with distributor) while the engine was running. If the engine idle doesn't change then you've found the bad cylinder/coil/plug.

Registered

Question? I have a po301 when the engine temp is cold. after it reaches 40C an I restart the engine it runs perfect.??
I replaced a couple hoses that were bad figured that would be too easy. I recently did a head gasket and new tensioner unit, hoses bla bla.....
I replaced the MAF sensor unit ordered online new and the top speed issue went away. still once it cools down I need to limp for about 5 minutes...

Any thoughts or could it be cam position sensor at the front of the engine?

Administrator 2009 SLK 55 AMG/Founding Member 2006

Question? I have a po301 when the engine temp is cold. after it reaches 40C an I restart the engine it runs perfect.??
I replaced a couple hoses that were bad figured that would be too easy. I recently did a head gasket and new tensioner unit, hoses bla bla.....
I replaced the MAF sensor unit ordered online new and the top speed issue went away. still once it cools down I need to limp for about 5 minutes...

Any thoughts or could it be cam position sensor at the front of the engine?

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